szajih

I believe that the use of ip unnumbered is less common than it was at some times in the past. But it still works. It is difficult to say much without knowing more about your issue. In general I would say that I have used ip unnumbered without having problems with it. I have customers who have used ip unnumbered in production networks and have not had problems with it.

Perhaps there are some issues with particular ways to try to use ip unnumbered. But we do not know how you were trying to use it. So there is not much that we can say about your problem.

HTH

Rick